Two correspondents, Julian Echave, and another, privately, questioned the crudeness of this concept.

One way of responding to what they said is to note that, for example, from a Bayesian perspective, the binary shift in beliefs is a bit of a nonsense.

Mind changing perhaps could mean, from this perspective:  given a binary choice between two policy options [say, minimum wage or no], my posterior probability mass on the event that a minimum wage of a given level would have such and such an effect on employment outcomes shifted – in the light of evidence – such that my binary choice shifted from preferring no minimum wage, to supporting one.